From 6d0c19341b7a85d507c3ec4967bab5f83b0fad8d Mon Sep 17 00:00:00 2001
From: Mark Rushakoff <mark.rushakoff@gmail.com>
Date: Wed, 7 Oct 2020 22:05:28 -0400
Subject: [PATCH] cmd/go: break after terminal loop condition

After the first time needCostly is set to true, there is no need to
continue checking the remaining args.
---
 src/cmd/go/internal/envcmd/env.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/cmd/go/internal/envcmd/env.go b/src/cmd/go/internal/envcmd/env.go
index 59d0ded658..dde68c1f0c 100644
--- a/src/cmd/go/internal/envcmd/env.go
+++ b/src/cmd/go/internal/envcmd/env.go
@@ -217,6 +217,7 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 		needCostly = true
 	} else {
 		needCostly = false
+	checkCostly:
 		for _, arg := range args {
 			switch argKey(arg) {
 			case "CGO_CFLAGS",
@@ -227,6 +228,7 @@ func runEnv(ctx context.Context, cmd *base.Command, args []string) {
 				"PKG_CONFIG",
 				"GOGCCFLAGS":
 				needCostly = true
+				break checkCostly
 			}
 		}
 	}